I often have to keep multiple ssh sessions open in different terminal windows at the same time and I'd like to have a differen background color to help me visualize to which host I'm connected to: i.e. red when I'm root@live-system. I tried configuring xfce terminal but the setting is not wi

The standard gnome-terminal has profiles. Just click right on the window and you'll see the menu entry.

You can create as many profiles as you like, each with their own colours, fonts, settings, and whatever, and switch freely between profiles whenever you wish.

I don't know if it's possible to have it switch profile automatically, but there's a command line parameter to load a config, and the File -> New menu option lets you choose a profile, so you can probably arrange separate launchers or something, if that helps.

Roxterm allows for changing of profiles from the command line, but I have found it insufficient for my needs since I didn't find a clean method to trigger the changes. Creating a new terminal tab or a new terminal window maintains the settings from the original.